Dietary Needs of Young Swimmers: Calorie and Nutrition Strategies for the Growth Period

Introduction

Swimming is an aerobic sport with high energy expenditure, and the body’s thermoregulation mechanisms in water make calorie demands higher than land-based exercise of equivalent intensity. For young athletes still in rapid growth phases, “eating right” is just as important as “swimming right.” However, many Taiwanese families with teenage swimmers still rely on rough concepts such as “eat more protein” or “don’t eat too much” when it comes to sports nutrition. This article provides a more systematic nutritional strategy for young swimmers.

Basic Calorie Requirements for Growing Swimmers

Compared with same-age peers, swimmers training more than 10 hours per week have significantly higher calorie needs:

The figures above are estimated ranges; actual needs vary by body type, training intensity, and growth rate.

Relative Energy Deficiency in Sport (RED-S) Warning: If young athletes have chronically insufficient calorie intake, symptoms such as stunted growth, persistent fatigue, stagnant performance, or menstrual irregularities in females may appear. Immediate evaluation by a sports dietitian should be sought.

Distribution Strategy for the Three Macronutrients

Carbohydrates: The Primary Energy Source

Carbohydrates should account for 50–60% of a swimmer’s total calories. Rice, noodles, and root vegetables common in Taiwanese food culture are excellent carbohydrate sources.

Carbohydrate choices before training (1.5–2 hours prior):

• White rice + steamed egg (easy to digest)
• Whole wheat toast + peanut butter
• Banana + low-fat milk
• Avoid fried and high-fat foods (they slow digestion and may cause discomfort in the water)

Carbohydrate replenishment after training (within 30 minutes):

• A 4:1 (carbohydrate:protein) ratio is most effective for glycogen resynthesis
• Sweet potato + eggs, or sports drink + milk, are both convenient options

Protein: The Foundation of Growth and Repair

Protein requirements for teenage swimmers are 1.4–1.7 g per kilogram of body weight per day (higher than the 1.2–1.6 g for adult athletes).

Quality protein sources commonly available in Taiwan:

• Tofu, dried tofu (plant-based, economical)
• Eggs (complete amino acid profile)
• Chicken breast, fish (low-fat, high-protein)
• Low-fat milk, yogurt (contain calcium, especially suitable during growth)
• Edamame (a plant-based option rich in essential amino acids)

Fat: An Essential Nutrient for Growth That Cannot Be Overlooked

Many parents mistakenly believe that young athletes should minimize fat intake, but fat is indispensable for hormone synthesis (including growth hormone), brain development, and absorption of fat-soluble vitamins. It is recommended to account for 25–30% of total calories, with an emphasis on unsaturated fats.

Key Micronutrients: Special Attention During Growth

Teenagers who train in indoor swimming pools in Taiwan have a higher rate of vitamin D deficiency due to insufficient sun exposure; regular monitoring of blood vitamin D levels is recommended.

Hydration: You Can Dehydrate in the Water Too

Many teenagers (and parents) do not realize that swimming can also cause dehydration. The aquatic environment reduces awareness of sweating, and athletes often reach mild dehydration (1–2% body weight loss) without realizing it.

Recommended hydration strategy:

• 2 hours before training: drink 400–600 ml of water
• During training (every 20 minutes): 100–150 ml of water or electrolyte drink
• After training: replenish 1,200–1,500 ml of fluid for every 1 kg of body weight lost

Practical Recommendations

Key daily meal planning points for parents:

1. Breakfast must be substantial (25–30% of daily calories), especially important on training days.
2. Provide a snack containing carbohydrates and protein within 30 minutes after training (such as milk + rice ball).
3. If the child has poor appetite after training, consider offering a more substantial main meal before swimming.
4. Avoid having athletes restrict their diet “for body shape”—the risks of calorie restriction during adolescence far outweigh those in adulthood.

Daily habits for athletes:

1. Carry a water bottle at all times and drink at least 200 ml before and after each training session.
2. Do not delay eating more than 45 minutes after training—make the most of the golden recovery window.
3. Eat dark-colored vegetables at least three times a week to supplement iron and antioxidants.

Conclusion

The nutritional needs of teenage swimmers have the dual characteristics of “high energy expenditure of athletes” and “special needs during growth,” which means general dietary advice is often insufficient to meet their requirements. If Taiwan’s youth swimming development system can incorporate sports nutrition education into a structured curriculum, equipping coaches, parents, and athletes alike with foundational nutritional knowledge, it would be a high-return-on-investment intervention strategy for improving overall performance.

Related Reading

• Special Nutritional Needs of Adolescent Swimmers: Dietary Strategies During Growth
• Nutritional Needs of Adolescent Swimmers: Calories and Micronutrients During Growth
• Dietary Strategies for Swimmers: Weight Management and Carbohydrate Loading Plans Within the Season
• Nutrition for Young Athletes: Calculating Calories for Growth Needs and Training Demands